Printing telegraph apparatus



April 14, 1942.

FIG. I

W. J. ZENNER PRINTING TELEGRA H APPARATUS Filed May 22, 1936 3 Sheets-Sheet 1 INVENTOR WALTER J.\ ZENNER BY I M ATTORN April 14, 1 942.

J. Z ENNER' PRINTING TELEGRAPH. APPARATUS Filed May 22,- 1936 FIG. 2

s SheetS-Shet ;2

lNVENT-OR WALTER J. ZENNER BY .v

ATTORNEY v Apri l14, 1942. W V ZENNER 2,279,609

PRINTING TELEGRAPH APPARATUS Filed May 22, 1936 3 Sheet-Sheet 5 FIG. 3

INVENTOR WALTER J. ZENNER M I ATTO'RNE Patented Apr. 14, 1942 S TAT E S 7 PRINTING TELEGRAPH APPARATUS tion of Delaware Application May 22, 1936, Serial No. 81,166

37 Claims.

This invention relates to printing telegraph apparatus, and particularly to a type wheel printer.

An object of the invention is to provide a simple, efiicient, compact, and inexpensive telegraphic recorder.

The invention features an escapement mechanism associated with the type wheel ofthe printer and consisting of a pawl and toothed drum for controlling the positioning of the type wheel in accordance with signal impulses received by a selector magnet.

Briefly, the printer includes a pair of motor driven shafts, one of which carries a type wheel and a ribbed selecting drum, and the other of which carries selecting and operating cams. A selector magnet, the armature of which is actuated cyclically by a selector cam and is held when the magnet is energized by certain signal impulses, controls a pawl latch which straddles the ribbed selecting drum. Each arm of the pawl is provided with an escape tooth which may be brought into engagement with a rib on the selecting drum when the pawl is'rocked right or left. The pawl is. spring urged for rotation in one a.

direction and is cyclically freed by a cam for rotation in response to the urging of the spring, if it is simultaneously freed by a latch controlled by the selector magnet. The cam restores the pawl to its. opposite position against the tension of the spring- Another cam causes the pawl to travel from one end of the ribbed drum to the other during a cycle of operation of the printer, after which the pawl is spring restored to its normal position. The ribs of the drum are of several difierent lengths in accordance with a predetermined plan, and by virtue of the combined rocking and translational movement of the pawl, the rotation of the ribbed drum is con,- trolled. The type wheel is rigidly secured to the drum, and the position to which the drum has been rotated during a cycle of operation of the selecting mechanism determines the type character that will be presented in cooperation with a printing platen to make an impression on the tape. Printing and tape feeding operations are eifected by a cam carried by the selector cam shaft.

For a complete understanding of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawings in which Fig. 1 is a front elevation partly in section of a printing telegraph mechanism in accordance with the invention;

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a sectional view taken approximately on the line 3-3 of Fig. 2;

Fig. 4 is a sectional View taken on the line 4-4 of Fig. 3;

Fig. 5 is a delevopment of the cylindrical por tion of the escapement drum;

Fig. 6 is a plan view of the disc portion of the escapement drum; 1

Fig.7 is an elevational view of the escapement drum and pawl as viewed from the left, and

Fig. 8 is a combined timing chart and cam outline chart.

Referring now to the drawings in which like reference numerals designate corresponding parts throughout the several views andparticularly to Fig. 1, the reference numeral ll indicates generally a keyboard transmitter mechanism which may be of any desired form such as the one disclosed in UnitedStates Patent 1,595,- 4'72, granted August 10,1926 to Howard L. Krum. The keyboard transmitter II includes a base casting l2 which carries a plurality of character selecting key levers E3. The key levers are operable upon a set of permutation bars (not shown) to control transmitting apparatus indicated generally by the reference character M.

The transmitting apparatus includes a transmitting cam shaft I6 which carries a plurality of transmitting cams l'l, only one of which is shown in the drawings. There is a contact controlling bell crank lever 18 associated with each of the transmitting cams H. The outer end of one arm of each of the bell crank levers I8 is disposed in engagement with one spring of a pair of transmitting contact springs l9 and the outer end of the other arm is aligned with a lever 2| which is controlled by the permutation bars (not shown) and which has a tongue 22 which is moved into or out of position above the end of the-contact controlling bell crank lever it. Each of the transmitting cams i1 is provided with a notch (not shown) into which a lu-g 23 of the bell crank,

lever 18 whichv follows the contour of the transmitting cam I"! may drop if the lever I8 is not restrained from counterclockwise rotation by the tongue 22 on the controlling lever 2|. When the lug 23 enters a notch in the transmitting cam H, the contact controlling lever I8 rocks counterclockwise and in so doing, permits the contact springs 19 to come into mutual engagement, thus impressing an impulse on the telegraph line to which the transmitter is connected. A locking bail 2 3 has a portion which follows a cam 26' on .of impulses representing a character.

the transmitting cam shaft and has a knife edge 21 which prevents shifting of the levers 2| during the transmission of a set of signals representing a character.

The base casting l2 supports vertical plates 36 and 3| (Fig. 1), in which are rotatably supported in suitable anti-friction bearings 32, receiving printer shafts 33 and 34. Mounted between the plates 30 and 3| on the base casting I2 is an electric motor 36, the rotor shaft of which carries a pinion 31. The shaft 33 has fixed thereto a gear 38 which meshes with the pinion 31 and the shaft 34 has fixed thereto a gear 39 which also meshes with the pinion 31. The shafts 33 and 34 are continuously driven by the motor and the shaft 33 drives selecting and controlling cams while the shaft 34 effects rotation of the type wheel of the printer.

On the front of the vertical plate 3| there is mounted a selector magnet 4| (Figs. 1 and 3) which forms a part of a selecting mechanism which will be described briefly, but for a more complete understanding of which reference may be had to United States Patent 1,937,376 granted November 28, 1933, to Walter J. Zenner. selector magnet 4| is provided with an armature 42 which constitutes one arm of a bell crank lever 43 that is pivoted at 44. The other arm of the bell crank lever 43 has a follower portion 46 which is adapted to follow a flutter cam 41 carried by the shaft 33. The flutter cam 41 is one of an assembly of cams confined between discs 48 and 49 of friction clutches 5| and 52, respectively (Fig. 2). The bell crank lever 43 is biased by a spring 53 in a clockwise direction to'draw the follower portion 46 into engagement with the cam 41 and the armature 42 away from the pole face of the selector magnet 4|. The cam assembly confined between friction clutch discs 48 and 49 includes a stop arm 54 in the path of rotation of which is disposed a stop gate (not shown), the operation of which is controlled by a plunger 56 in a manner clearly described in the above mentioned Patent 1,937,376. The plunger 56 is controlled by the armature 42 in such manner that the stop gate (not shown) is latched to prevent rotation of the stop arm 54 when the armature 42 is in engagement with its pole face, and is released to permit the stop arm and its associated cam assembly to rotate when the armature 42 is withdrawn from engagement withits pole face.

When the stop gate (not shown) releases the stoparm for rotation, the flutter cam 41 is rotated, and as this cam is provided with a plurality of apices, the bell crank lever 43 which has the portion 45 following the flutter cam 41 is rotated impulse, the armature 42 will be held and the bell crank lever 43 will clockwise under the influence of the spring 53 not be free to rotate when an apex of the cam 41 passes out of alignment with the cam follower 46. The number of apices on the cam 41 corresponds to the number The code which is intended to be employed for the operation of this printing mechanism is a start-stop permutation code.

The cam assembly carried by the shaft 33 includes a cam 51 having a plurality of apices and The against which rides a cam follower portion 58 (Fig. 3) at one end of a three-armed lever 59, which is journalled on a bushing 6|! carried by a bracket 55. One arm 6| of the three-armed lever 59 is bifurcated as shown at 62 and a spring 63 connected to the arm 6| tends to rotate the three-armed lever 59 counterclockwise. Another arm 64 has a portion 66 formed perpendicularly at the end thereof in alignment with a hook portion 65 of an arm of the selector bell crank lever 43. When the three-armed lever 59 and the bell crank lever 43 are in their extreme clockwise positions, the arm 64 is engaged and held by the hook portion 65 of the bell crank lever 43 and the lever 59 is incapable of rotating counterclockwise in response to the urging of the spring 53, even when an apex of the cam 51 passes out of alignment with the follower portion 58. However, when the bell crank lever 43 is in its extreme counterclockwise position, the lever arm 64 is disengaged from the hook portion 65 of the bell crank lever 43 and three-armed lever 59 can rotate counterclockwise when a low portion of the cam 51 is aligned with the cam follower 58.

Slidably and rotatably mounted in the bushing 60 and arm 15 of bracket 55 is a slidable rock shaft 61 to which is fixed a pawl 68. Intermediate the arms of the pawl there, is a perpendicularly extending arm 69 which is disposed within the bifurcated portion 62 of the previously described arm 6| of three-armed lever 59. The pawl 68 straddles and controls the rotational escapement of a ribbed drum 1| which is mounted on a bushing 19 fitted over the shaft 34, which carries an arm 12 disposed within a notch of a friction disc 13 of a friction clutch mechanism 14 carried by the shaft 34. The friction disc 13 tends to rotate the bushing 10 and drum 1| and does, in fact, rotate them when the pawl 68 permits such rotation. A type wheel 16 having characters arranged around the periphery thereof is mounted on the shaft 34 and is secured to the bushing 16 to rotate therewith.

The pawl 68 is relatively thin with respect to the length of the ribbed drum 6| and is adapted to cooperate with various portions of the surface thereof during a cycle of operation of the printer. The slidable mounting of the rock shaft 61 permits the pawl to traverse the drum from one end to the other during a cycle of operation, and for this movement, a lever 11 pivoted at 18 to a fixed portion of the apparatus has an end disposed within a recess in the shaft 61. Intermediate its ends the lever 11 has a cam follower portion 19 which cooperates with a cylindrical cam 8| included in the cam assembly carried by the shaft 33. The cam surface of the cam 8| is at the side thereof and consists of alternate rises and dwells. The cam follower 19 engages the cam surface and as the cam rotates the lever 11 is gradually rocked counterclockwise, as viewed in Fig. 4, against the tension of a spring 82, until the cam follower 19 rests upon the outermost portion of the cam surface, which marks the extreme point of counterclockwise rotation of the lever 11, after which the cam follower 19 drops off the cam surface and the spring 82 restores the lever 11 to its extreme clockwise position. By virtue of the previously described articulation of the lever 11 to the shaft 61, the pawl 68 traverses the ribbed escapement drum 1| as the lever 11 is operated by the cam 8| and is suddenly restored to its normal position by the spring 82 when the cam follower 19 is released from engagement with the cam surface of cam 81.

As previously described, the perpendicularly extending arm 69 of the pawl 68 is disposed within the bifurcated portion 62 of the lever arm BI and all rocking movements which the threearmed lever 59 undergoes during a cycle of operation of the printer will be imparted to the pawl 68 as the cam 81 causes it to traverse the escapement drum I l.

The particular embodiment of the printer shown in the drawings is intended for operation on a five-unit permutation code which afiords thirty-two selective possibilities. Other codes contemplating greater or lesser numbers of impulses may be employed and a greater or lesser number of selective possibilities thus afforded. Since in the present embodiment thirty-two code combinations may be obtained, it is possible to select thirty-two positions of the type wheel. Accordingly, the ribbed drum 1 I, the escapement of which is controlled by the pawl 68, is provided with thirty-two ribs or teeth of different lengths in accordance with a predetermined plan, uniformly spaced around the periphery of the drum. In its preferred embodiment, the escapement drum has sixteen ribs uniformly spaced around the periphery thereof and an end plate,

which has sixteen teeth also uniformly spaced,

is adapted to be applied to the drum so that each tooth of the end plate or disc is disposed between two ribs of the drum.

In Fig, 5 there is shown a development of the surface of the escapement drum with the ribs arranged thereon according to the preferred plan and in Fig. 6 is shown a plan view of the end plate or disc with the sixteen teeth. The reference numeral H which designates the drum in the other figures designates the developed view of the drum in Fig. 5, and the reference numeral 83 indicates the toothed disc in Figs. 6 and '7. It will be observed that a rib 84 extends across the drum from end to end thereof, and that half way around the drum there is a rib 86 which is shorter than the rib 84 by a distance approximately equal to the distance by which the ribs of the drum overlap the. toothed disc. Intermediate the ribs 84 and 8'5 in both directions are ribs 8'! which differ in length from rib 85 by approximately the same amount that the rib 85 differs from rib 34. Intermediate the ribs 84 and 81 and 88 and 8'! are ribs 88 which are shorter than the ribs 81. Intermediate any two ribspreviously mentioned are ribs 89 which are shorter than the ribs 88. shorter than the ribs 89. The escapement drum 7! will thus be seen to consist of one rib at, one rib 86, two ribs 8'], four ribs 88, eight ribs 89., and sixteen ribs 9! of lesser extent in the order named, and totaling thirty-two ribs. The progress of the pawl 68 in traversing the. drum H is toward peripheral bands containing increasing numbers of ribs. Thus, if the pawl is rocked as it passes from the first or zero perpiheral band which is the upper band in Fig. 5,. into the peripheral band corresponding to the first signal interval, the drum will be permitted to rotate through one-half revolution before it is stopped by engagement of the pawl with ribBB. It may rotate through one-quarter of a revolution during the second signal interval in being released by rib 84 or B6 to be stopped by a rib 81. It may rotate one-eight of a revolution during the third signal interval in being released by a rib 83, 83, or 81 to be stopped by a rib 83. It may rotate The teeth 9! of disc 83 are through one-sixteenth revolution during the fourth signal intervat in being released by a rib. 8'4, 86, 81, or 88 to be stopped by a rib 8.9; Lastly, it may rotate through one thirty-second of." a. revolution during the fifth or final signal interval in being released by any of the ribs, mentioned above to be stopped by a rib 9|. In this manner, the drum ll may be stopped in any one of the possible thirty-two positions by rocking the pawl 68' or preventing it from rocking during predetermined intervals of the cycle in which it traverses the drum H. The type wheel 16 is controlled by the escapement drum and therefore: it may be brought to any one of thirty-two selective positions.

As indicated in Figs. 1 and 2,v the base casting 12 supports a plate 92 directly below the. type wheel l6 and the selecting drumJl, which plate carries tape feeding mechanism, a tape guiding channel, a printing platen, and a type wheel inking roll- The tape guiding channel is shown at 943., Fig. 1, and'the tape feed roll is shown at 94-. A pressure roll 96- carried on a pivoted arm 9? which is spring urged in a counterclockwise di-- rection as shown in Fig. 1, maintains the tape in. engagement with the feed roll 94. A flange 98' retains the tape in the desired alignment over the feed roll. A ratchet wheel 99 (Figs. 2 and 3) which isactuated by a feed pawl It! rotates the.

feed roll .l lto advance the tape tothe printing point. As shown in Fig. 3, a printing platen M32 is carried at the end of an arm: I03 which is pivotally mounted at m and. is urged in counterclockwise direction by a spring N36. The platen arm. N33 has an. acute angled portion It! which is disposed above and in. alignment with a rotatable ratchetwheel H38. The ratchet I58 is rotated by a pawl 19 and as it rotates, it cams the acute angled portion Ill-l of theplaten arm I03 and thus lifts the platen. Hi2 to press the tape,

upon which charactersare to be printed, against ie type wheel to receive an impression. The. tape. feeding pawl ltl and. the platen operating. pawl [B9 are articulated at i I! to a lever I I2. which is. pivoted at I I-3 and at its upper end follows a cam l 14 included in the cam assembly frictionally driven by the shaft 33. As shown in Fig. 3,. the drop from the highest portion to the lowest portion of cam H4 is abrupt, and when the upper end. of lever I I2 drops from the highest to the lowest part of the cam, the lever is suddenly I and sharply rotated in a clockwise direction. which, through the pawl Hi9 and platen ratchet. 88,.causes the platen arm m3 to be sharply rotated clockwise, whereby the platen m2 strikes. the tape, against the type wheel vigorously. The feeding of the tape occurs as indicated in Fig. 3, somewhat gradually as the lever H2 is rotated counterclockwise by the rotation of the cam IM.

In the operation of the printer, the selector magnet M is energized and deenergized in accordance with signals impressed upon the telegraph line to which the magnet is connected.

The armature E2 is periodically moved into engagement with its pole face through the operation of cam ll, upon bell crank lever 43, and when the magnet is energized at the time the armature approaches its pole face, the armature is held and the three-armed lever 59 is released from retained engagement with the hook portion 57 of the bell crank lever 53. The cam 51 then permits the three-armed lever 53* to rotate counterclockwise, withdrawing the right-hand escape tooth of pawl 6-3 from engagement with a rib of the escapement drum H and permitting it to re.

tate until it is stopped by the engagement of the left-hand arm of the pawl with a rib. The timing of the apparatus as between the cams 41 and 51 is such that if the armature42 is not held due to energization of the selector magnet 4 I, the bell crank lever 43 returns to its extreme clockwise position before the cam 51 releases the three-armed lever 59. Thus, when a marking signal is received which is evidenced by energization of the selector magnet, the pawl 68 is permitted to rock and the escapement drum is permitted to rotate, but when a spacing signal is received, the armature 42 is not held and the three-armed lever is unlatched and latched by the hook 65 before the cam 51 can release the three-armed lever for operation.

It will be understood that the cam 57 restores the three-armed lever 59 and the escapement pawl 63 to their extreme clockwise positions after they have rotated to their counterclockwise positions. As a combination of markin and spacing signals representing a character is received, the escapement pawl 68 travels the length of the escapement drum, due to the operation of the lever 11 by the cam 8|. Movement of the pawl longitudinally of the drum is intermittent and as the pawl rocks or remains unrocked, due to the reception of marking or spacing signals, the escapement drum rotates or remains stationary in accordance with received signals, until the pawl comes into engagement with one of the teeth of the toothed disc 9| or one of the ribs intermediate those teeth. This completes the selection, whereupon the lever I I2 operates and causes the platen 02 to imprint the selected character upon the tape. Thereafter the cam 8| frees the lever 11 and permits the spring 82 to restore the escapement pawl 68 to its foremost position. This releases the escapement drum for rotation and it rotates to its normal or idle position which is with th right-hand escape tooth N6 of the escapement pawl 68 in engagement with the rib 84 at the foremost portion thereof. During the next cycle of operation and specifically while the selection of the printing position of the type wheel is being completed, the lever I 12 rotates the tape feeding ratchet 99 and feeds a. blank portion of the tape into alignment with the printing position of the type wheel.

The operation of the printer being now understood, attention is directed to Fig. 8 wherein is displayed the timing of operations by reference to their operating members. The reference numeral l2! designates a representation of the intervals of which a start-stop permutation code signal is composed, which are start impulse interval, signal impulse intervals I, 2, 3, 4, and 5, and stop impulse interval. The signal impulse intervals may be and usually are of equal lengths, and the signals transmitted and received during said intervals may be either marking or spacing in any permutative order.

The irregular line 41a represents the flutter or armature operating cam 41, and indicates that said cam has an apex for each signal impulse interval, and one for the stop interval. The preferable timing of cam 41 with respect to the signal intervals is, as shown in Fig. 8, such that the cam follower 46 rides onto an apex near the middle of an interval and falls away abruptly unless theselector magnet is energized and the armature thereby attracted.

The line 51a relates to the timing of the escapement pawl cam 57. This cam, it will be observed, has five apices, corresponding to the five signal intervals. Cam 5'! and its follower 58 are so disposed with respect to cam 4'! and its follower 46 that cam follower 58 falls away from an apex slightly later in a signal interval than the falling away of cam follower 46. This time difference in the descent of the two cam followers accounts for the previously described circumstance that if the follower 4B falls away from an apex, due to deenergized condition of the magnet, the three-armed lever 59 and the escapement pawl which it controls cannot rotate counterclockwise when the follower 58 falls away from an apex due to latching of the lever arm 64 by the hook 61.

The line I I40, relates to the operation of printing and tape feeding cam H4. This cam, it will be observed, has one apex, the rise to which is very gradual, being extended over substantially the full periphery of the cam, and the descent from which is very abrupt. The apex is so positioned with respect to the cams 41 and 51 that its follower falls away just after the escapement pawl 68 has been restored to its extreme clockwise positionby the cam 51 following release for counterclockwise rocking by the apex of cam 5'! which corresponds to the fifth signal interval. This line thus indicates graphically'the previously stated fact that the printing platen is actuated violently just after the type wheel has been brought to its selected position, and that the tape is fed gradually during the next selecting cycle of the escapement drum.

The line 81a indicates generally the contour of the cam 81 which causes the escapement pawl 68 to traverse the escapement drum H from end to end. It will be noted that the cam 8| is so positioned with respect to the other cams that it begins to move its follower early in the first signalling interval. The cam surface consists of alternate rises and dwells, there being a rise effective to move the escapement pawl during a portion of each of the signal intervals. Thus the escapement pawl traverses the drum intermittently in steps coordinated with the signal interval until the end of the drum is reached after which the follower falls away to the lowest level of the cam thus permitting the escapement pawl 68 to be restored to its normal or initial position where it remains until being shifted again upon the reception of another series of signal impulses.

The provision of alternate dwells and rises on cam 8| enables the movement of the pawl longitudinally of the drum to be coordinated accurately with respect to the signal intervals. It is apparent that the time intervals during which the drum rotates decrease as successive signal intervals in a given signal combination are traversed, the reason being that as the pawl advances to peripheral areas of the escapement drum in which the ribs increase in number, the drum rotates through progressively smaller angles. The timing of the translational movement of the pawl with respect to its rocking movement is not especially critical during the first three or four intervals, and the cam 8| could, if desired. be so constructed as to move the pawl continuously during the first three or four signal intervals, but if the escapement pawl shifting cam follower moves steadily during the fifth signaling interval, or during any subsequent intervals which might be provided in connection with codes of more than five units, there is a possibility that the pawl may be shifted longitudinally of the drum at the wrong instant and into engagement with the wrong rib or tooth. This possibility is eliminated by causing the cam follower I9 to stand idle for a brief instant during each signal interval.

It will be noted that in point of time the escapement pawl is restored to its initial position.

front) has a rearward offset, so that the escape tooth II'I of that arm is displaced rearwardly from the escape tooth IIB of the other arm a distance substantially equal to the previously described difference in the length between any escapement rib and the next shorter rib. When the pawl is rocked counterclockwise to Withdraw ethe right-hand escape tooth HS from engagement with a rib thus permitting the escapement drum 'II to rotate, the left-hand escape tooth II! is then in thepath of the next shorter rib and will stop the drum when that rib is encountered even though the pawl should not be shifted immediately, as when pawl shifting cam follower encounters a dwell. If, however, the two escape teeth were disposed in the same plane, it would be necessary to shift the pawl suddenly as soon as the escapement drum should be released for rotation in order that the left-hand escape tooth II! should be shifted into the path of the next shorter rib before that rib could rotate past the escape tooth.

Referring to Figs. 1 and 7, attention is directed to a cam disc I22 which is fixed to the drum and rotates therewith and to a pin I23 carried by the left-hand arm of the escapement pawl 68. These elements permit the type wheel shaft, type wheel, and selecting drum to be operated at a lesser velocity than could be employed in the absence of the disc and pin. Rotation of the type wheel at reduced speed is desirable because of the very frequent stopping of the type wheel for printing.

The cam I22 and pin I23 cooperate to overcome, at the beginning of a cycle of operation, a condition that may arise as a result of the inertia characteristics of the escapement drum and type wheel. The apex I 24 of the cam I22 extends a sufficient distance from the axis of the cam to engage the pin I23 and hold the escape tooth II'I out of engagement with the selecting drum 'II, thus holding the pawl 68 in its extreme clockwise position under conditions when it might otherwise be released for counterclockwise rotation. When the signaling impulse received during the first interval is a marking signal, the pawl 68 rocks in a counterclockwise dizection under the influence of the spring 63 to withdraw the right-hand escape tooth IIB from engagement with the rib 84 and to place the escape tooth II! in the path of that rib. It is possible that the inertia of the type wheel and selecting drum may delay the response of those elements to the driving force of the friction clutch and thus the drum and type wheel may lag with respect to incoming signal impulses. .A marking impulse in the first interval as previously set forth indicates and establishes a condition for selection of a character in the second the'type engagement of the right-hand escape tooth III;

with the rib 81 in the second half of the drum. If the rib 35 has not passed the left-hand escape tooth II! at the time the marking signal in the second interval is received, that tooth will drop into the path of the rib 84 and will stop f the drum before it has completed 18'0" of rot'a tion from its initial position. When the escapement pawl is restored to its normal or extreme clockwise position, the right-hand escape tooth H6 will stop the escapement drum by engage ment with the rib 8'6 in'stea'dof by engagement with the rib 81 at a point farther along the periphery of the drum.

During the interval in which the pin I23 rides on apex I of cam I22, the pawl is unable't'o respond to a marking signal andit'is released to respond to such signal as soon as the pin I23 falls away from the apex 'I24- of cam I22. It is by means of this arrangement that the lefthand escape tooth II! of the pawl 68 cannot interfere with rotation of the escapementdrum through the proper angular distances in accordance with the received signals. 'The' cam" I22 and pin I23 do not interfere with the selection of a final stop position of the drum with the cam apex in alignment with the pin I23 forthe reason that by the time the apex I24 of the cam has rotated into such alignment the pawl 6'8 has been shifted longitudinally of the escape ment drum by the cam BI and thus the pin I23 has been moved out I24 of 0am I22.

The inking of the type wheel It is accomplished by means of an ink supplyroll I26 which is rotatably mounted on pivoted arm I21 and which is biased into engagement with the periphery of the type wheel I6- by means of spring I28. Thus as the type Wheel isrotated, the char-'- of'the path of the apex acters carried on the periphery thereof are successively inked by engagement with theinked roll I26 and are thus conditioned for transferringan impression to the tape by operation of theprintingplaten I 02. 1

Although a specific embodiment of the i'nvention has been disclosed and described herein,

it is to be understood that the apparatus and the manner in Which it operates are capableof rearrangement, modification, or substitution Without departing from the'spirit of the invention and within the scope of the appended claims.

W hat is claimed-is:

1. In a printing telegraph receiver, a type wheel, means for rotating the type wheel, fa ribbed drum for controlling the rotationof the type wheel, a pawl for controlling the. drum, signal controlled mean's for oscillating the pawl, and 1 means for shifting the pawl longitudinally-of the drum. I

2. In a printing telegraph receiver, a type wheel, means forxrot'ating the type wheel, a ribbed drum associated with the type wheel, a pawl oscillatable in two directions for controlling. the extent of rotation of the" drum; and means for oscillating the pawl.

response 3. In a printing telegraph receiver, a type wheel, means for rotating the type wheel, a ribbed drum associated with the type wheel, a pawl for controlling the drum, means for shifting the pawl longitudinally of the drum, and means responsive to signal impulses for rocking the pawl intermittently.

4. In a printing telegraph receiver, a type wheel, means for rotating the type wheel, a drum associated with the type wheel having a plurality of ribs of varying lengths, a pawl for controlling the drum, and means for associating the pawl with different ribs and with different portions thereof during a signaling cycle.

5. In a printing telegraph receiver, a type wheel, means for rotating the type wheel, a drum associated with the type wheel having a plurality of ribs beginning at various points longitudinally of the drum and terminating at an end thereof, a pawl for controlling the drum, means for rocking the pawl, and means for shifting the pawl longitudinally of the drum toward areas having increasing numbers of ribs.

6. In a printing telegraph machine, a type wheel, means for rotating the type wheel, a drum associated with the type wheel having a plurality of ribs extending longitudinally thereof, and a pawl for controlling the drum having escape teeth, one of said teeth being displaced longitudinally of the drum with respect to the other tooth.

7. A selecting mechanism for printing telegraph apparatus comprising a magnet having an armature, a rotatable cam shaft controlled by said magnet, a latch controlled by said armature, a pawl controlled jointly by said cam shaft and said latch, and aribbed escapement drum controlled by said pawl.

8. A selecting mechanism for printing telegraph apparatus comprising a magnet having an armature, a rotatable cam shaft controlled by said magnet, a latch controlled by said armature, a pawl capable of rotational and translational movements, means on said cam shaft for efiecting both of said movements, and'means controlled by said latch for blocking one of said movements.

9. In a selecting mechanism for printing telegraph apparatus, a signal responsive magnet having an armature, a rotatable cam shaft, a cam on said cam shaft for rocking said armature independent of signals, a latch lever carried by said armature, an escapement drum, a pawl associated therewith whoseposition is determined by said magnet armature, a cam on said cam shaft for rocking said pawl, and a lever carried by said pawl in cooperative relation to said latch lever. v

10. In a selecting mechanism for printing telegraph apparatus, an escapement drum having external ribs longitudinally thereof, a pawl straddling said drum for cooperation with the ribs thereof, a selector magent having an armature, and a rotatable shaft carrying a plurality of cams, one ofsaid cams operable to rock said armature, another of said cams operable to rock said pawl, and another of said cams operable to shift said pawl longitudinally of said drum.

11. In a selector for stopping a rotatable shaft, a cylinder carriedby said shaft having projections thereon, a reciprocable pawl disposed to be moved in two different planes with respect to the cylinder in cooperation with the projections to determine the rotation of said shaft, signal responsive means for controlling the movement CTI.

of saidpawl in one of said planes, and locally actuated means for controlling the movement of said pawl in the other of said planes.

12. In a telegraph receiver, a type wheel, a drum integral with said type wheel having variably arranged projections on the periphery thereof, pivotally and translatably movable means operative with said drum for controlling rotation thereof in steps to determine its position and the consequent position of the type wheel, and a signal responsive selector mechanism operative directly on said means to control pivotal movement according to signals and translational movement independently of signals whereby the selective position of the drum and type wheel may be determined.

13. In a telegraph receiver, a type wheel, means having a variable number of stop positions for determining the position of said type wheel, a cam shaft, an electromagnet responsive to line signals, and means under the joint control of said cam shaft and said electromagnet for determining the stop position of said means.

14. In a selector, a rotatable type wheel, a cylinder supporting a plurality of projections, a pawl, rotatable means for effecting relative movement between said cylinder and said-pawl, and signal control means for controlling the cooperative relation between said cylinder and said pawl to determine the rotation of said type wheel.

15. In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections and mechanism cooperating with said projections, a printing element, and signal controlled mechanical means for operating said mechanism and said printing element.

16. In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections, an electromagnet, a cam shaft released by said electromagnet for controlling the operation of said means in accordance with the operation of said electromagnet, and a printing element operated from said cam shaft following the operation of said means.

1'7. In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections, an electromagnet having an armature, mechanical means for moving said armature into magnetic relation to said electromagnet, and an escapement mechanism controlled by said armature in accordance with the energization of said electromagnet for determining the position of said type wheel through said drum.

18. In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections and a cooperating pawl, an electromagnet having an armature, mechanical means for moving said armature into magnetic relation to said electromagnet, and means under the control of said armature in accordance with the enaccordance with the energization of said electro-.

2,279,609 magnet for operating .said pawl in its several positions with respect to said drum to determine the position of said type wheel.

:20. .In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including .a drum having a plurality of projections, a pawl cooperatively associated with the projections on said drum, means for effecting relative movement between said pawl and said drum periodically during each signal interval, and an electromagnet responsive to line signals for determining the relative movement between the drum and pawl.

21. In .a printing telegraph receiver, a type whee-l, means controlling the position of said type wheel including a drum having a plurality of projections, a pawl cooperatively associated with the projections on said drum, cam means for effecting relative movement between said pawl and said drum .periodically during each signal interval, and an electromagnet responsiveto line signals for determining the relative movement between the drum and pawl.

22. In a .printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections, a pawl cooperatively associated with the projections on said drum, cam means for oscillating said pawl with respect to the projections on said drum periodically during each signal interval, and an electromagnet responsive to line signals for controlling the oscillation of said pawl and thus the escapement of said drum.

23. In a printing telegraph receiver, a type wheel, means controlling the position of said type wheel including a drum having a plurality of projections, an electromagnet having an armature, a pawl, mechanical means for progressively moving said pawl into cooperative relation with said projections, and means cooperating with said pawl following each progressive movement thereof in response to the control of said electromagnet for determining the position of said type Wheel.

24. In a printing telegraph receiver, a type wheel, means for rotating the type wheel, a drum ribbed on its periphery associated with the type wheel, a pawl oscillatable in two directions for controlling the extent of movement of the drum, means for oscillating the pawl, and a single electromagnet for initiating the operation of the receiver and subsequently controlling the action of the pawl with respect to the drum whereby the degree of rotation of the type wheel is controlled.

25. In a telegraph receiver, a rotatable shaft, a type wheel fixed to said shaft, an externally toothed member also fixed to said shaft, pivotally and translatably movable means cooperative with said member for controlling rotation thereof in steps to determine its position and the consequent position of the type wheel, and a signal selector mechanism responsive to permutation code signals and operative directly on said means to control pivotal movement according to signals and translational movement independently of signals whereby the selective position of the member and type wheel may be determined.

26. In a telegraph receiver, a rotatable shaft continuously under torque, a type wheel fixed to said shaft, a variably toothed escapement memher also fixed to said shaft, pivotally and translatably movable means cooperative with said member for controlling its position and the consequent position of the type wheel, and a signal selector mechanism responsive to permutation code signals and operative directly on said means to control. pivotal movement according to signals and translational movement independently of signals whereby the selective position of the member and type wheel may be determined.

27.111 a telegraphreceiver, a type wheel, a shaft-to which said type wheel is secured, means also secured to said shaft having variably arranged :stop projections on the periphery thereof for determining the position of said type wheel, a cam shaft, an electromagnet responsive to line signals, and means under the joint control of said cai n shaft and said electromagnet for determining the stop position of said means.

Ina telegraph receiver, a first shaft, a cam assembly operable intermittently by said shaft, electromagnetic means for controlling the rotation of said cam assembly, a second shaft. a variably toothed escapement member fixed to said shaft, a type wheel carried by :said second shaft in fixed angular relation to said escapement member, and means controlled jointly by said cam assembly and said electromagnetic means for controlling said escapement member and consequently said typewheel.

29'. In a telegraph receiver, an electromagnet responsive to line signals, a cam shaft operable in signal controlled cycles, a type wheel, means having a variable number of stop positions per cycle of said cam shaft for determining the position of said type wheel, and means under the joint control of said cam shaft and said electromagnet for determining the stop position of said means.

30. In a telegraph receiver, a type wheel, means for rotating the type wheel, a variably toothed escapement member for controlling the rotation of the type wheel, a pawl for controlling the rotation of the escapement member, and means for producing relative motion of translation between said pawl and said escapement member.

31. In a telegraph receiver, a type wheel, means for rotating the type wheel, a variably toothed escapement instrumentality for controlling the rotation of the type wheel, a pawl for controlling the rotation of the escapement instrumentality, and cam means for imparting oscillatory movement to said pawl and for producing relative motion of translation between said pawl and said escapement instrumentality.

32. In a telegraph receiver, a magnet having an armature, a rotatable cam assembly controlled by said magnet, a latch controlled by said armature, a pawl controlled by said latch, an externally toothed instrumentality controlled by said pawl, a type Wheel controlled by said externally toothed instrumentality, means included in said cam assembly for oscillating said pawl and means also included in said cam assembly for producing relative motion of translation between the said pawl and said externally toothed instrumentality.

33. In a printing telegraph apparatus, a type wheel, means for rotating the type wheel, an instrumentality connected to said type wheel having variably arranged peripheral projections, a member movable according to two characteristics for controlling the extent of rotation of said instrumentality, and signal controlled rotatable means for controlling the motion of said member.

34. In a printing telegraph apparatus, a type wheel, means for rotating the type wheel, an instrumentality connected to said type wheel having variably arranged peripheral projections, an escapement mechanism movable according'to two characteristics for controlling the extent of rotation of said instrumentality, and signal controlled rotatable means and signal responsive electromagnetic means for jointly controlling the motion of said escapement mechanism.

35. In a printing telegraph apparatus, a type wheel, means for rotating the type wheel, an in- ,strumentality connected to the type wheel having on the periphery thereof rows of projections varying in number according to a mathematical progression, escapement means operable with reference to successive rows of said projections for controlling the rotation of said instrumentality and consequently the rotation of said type wheel, signal controlled rotatable means for progressively conditioning said escapement means for rotation controlling cooperation with successive rows of said projections, and signal responsive electromagnetic means for controlling said escapement means jointly with said rotatable means.

36. A telegraph receiver in which a printed record is made from a typewheel, means to position the typewheel comprising stops, one for each printing position of the typewheel, said stops being located in groups, each grouphaving double the number of stops of the previous group, a

selector mechanism to selectively operate said groups of stops progressively from a smaller to a larger group to selectively position the typewheel whereby the degree of motion of said typewheel corresponding to the actuation of said last named stops decreases progressively and printing means to cooperate with said typewheel to effect printing, means to operate said printing means, and means to free said printing means from said typewheel before said typewheel positioning means comes to its normal stop position.

37. In a printing telegraph machine, a plurality of type faces, selecting mechanism comprising a plurality of stops adapted to be selectively controlled in response to code signals, means having a predetermined cycle of operation arranged to act upon said stops to position a desired type face into ultimate printing position when the last code signal is received and before a cycle of operation has been completed, printing means to cooperate with said type faces to effect printing, means to operate said printing means, and means to free said printing means from said type faces before said selecting mechanism and stop positioning means come to normal stop positions.

WALTER J. ZENNER. 

